Hello, Rebekah.

Infectious hepatitis can only be contracted by dogs, from other dogs and other members of the dog family, like infected foxes, for example.

The hepatitis virus is transmitted in urine, nasal or eye secretions of infected animals. The infected urine or secretions must come in direct contact with the susceptible dog.
http://www.sniksnak.com/doghealth/infectioushep.html

Eating frogs, toads or mice, should not cause hepatitis in dogs; however, if the toads are of the bufo marinus family, they contain toxins on their skin, which can make dogs extremely ill, or kill them. If a mouse who has ingested rat poison is eaten by a dog, they will, in turn, be poisoned by 'proxy'. Rat poison removes the clotting factor from the blood, and the dog can bleed to death, internally, if not treated immediately.

If your dog is being treated for hepatitis, I hope all is going well.

Cher